How is the Christian life and a submarine similar? One might be surprised at the similarity between the two. When submarines were first built, they were not equipped with any mechanism that allowed them to see above the water. They would blindly move through the water. In 1854, the earliest type of a naval periscope was designed that allowed those submerged underwater to see above water. With the help of periscopes, objects above water (ships, boats, etc) could be seen and focused on. The periscope was the eye of the submarine that directed its movements and actions.
In Colossians 3:1-2 the Bible says, “If ye then be risen with Christ, seek those things which are above, where Christ sitteth on the right hand of God. Set your affections on things above, not on things on the earth.” When a person gets saved, they become a citizen of heaven but still reside on earth. Earth is still our temporary residence until Christ calls us away. And we are called as believers, not to isolate ourselves from the world, but, rather, to live in the world. We are to be in the world, but not allow the world to be in us. We are to work, raise a family, pay taxes, love our neighbors as earth-dwellers. However, this verse tells us where our focus needs to be. We must constantly be “looking unto Jesus the author and finisher of our faith…” (Heb. 12:2). We must live here below for the time God has appointed, but we must never get our spiritual eyes focused on what’s below. We must continually be focused on that which is above. We must constantly look to that which is eternal. We must always be laboring to lay up treasure in heaven.
The Christian is constantly tempted to focus on the here-and-now while neglecting eternal realities. When we focus on the here-and-now, we are tempted to put down roots on earth instead of looking “for a city whose builder and maker is God” (Heb. 11:10). When we focus on the here-and-now, we are tempted to lay up “treasures on earth, where moth and rust doth corrupt, and where thieves break through and steal” instead of laying up “treasures in heaven, where neither moth nor rust doth corrupt, and where thieves do not break through nor steal” (Matt. 6:19-20). Our kingdom is not of this world. Our citizenship is heavenly. We must strive to pour out our lives for things that will impact eternity. We must constantly make decisions in light of eternity and choose things that will advance the gospel truth.
We are like the submarine submerged under water that uses its periscope to keep its focus above water. A submarine must know what is above water in order to know what to do and where to go. So it is with the Christian. A Christian whose mind in constantly upon heavenly things, will makes decisions that impact what they do and places they go.